The present invention pertaining to molding systems and is particularly directed to provision of clamping force in a desynchronously opened, stacked, multi-parting molding system.
A desynchronously opened, stacked, multi-parting molding system is described in U.S. Pat. No. 4,146,600 to Elly et al. The system essentially includes left, center, and right molding blocks for defining a left molding cavity between the left and center molding blocks and a right molding cavity between the center and right molding blocks along a common axis and positioning means for moving the left, center and right molding blocks with respect to each other for desynchronously opening and closing the left and right molding cavities, by retracting the first means. The positioning means also applies a clamping force to the molding cavities while both molding cavities are closed, by protracting the first means. The system further includes a locking means for maintaining one molding cavity in a closed position while the other molding cavity is in an open position so that substantial pressure can be maintained in the closed one molding cavity.
Whenever one molding cavity is opened, a clamping force is no longer applied by the positioning means to the molding cavity that remains closed. The only clamping force that is applied to the molding cavity that remains closed is whatever clamping force is applied by the locking mechanism that maintains the closed molding cavity in its closed position; and such clamping force is significantly less than that applied by the positioning means when both molding cavities are closed.